Many companies are actively seeking to create a display element that is easily manufacturable using roll-to-roll coating techniques. These display elements can be either active, i.e. emit light such as LED, OLED, PLED, EL, or passive, i.e. affect the passage, reflection or refraction of light such as LCD, CLC, e-ink etc. Some passive systems are bistable such they can be switched and remain switched after the power has been removed. Most configurations previously disclosed can be readily adapted to colour functionality.
Various electrowetting display elements are known in the prior art.
U.S. Pat. No. 6,473,492 discloses a fluid element device that rearranges fluid within a capillary tube. A voltage is used to move the fluid within the capillary to a desired level. US2002/0080920 discloses a filter device using an array of elements based upon U.S. Pat. No. 6,473,492 for use with X-ray imaging equipment. US2003/0085850 discloses an electrostatic device that changes a meniscus shape such that the focal length of the device changes.
U.S. Pat. No. 6,449,081 describes a focussing element based on the electrowetting phenomenon. WO2/002099527 describes a display element with a defined prismatic structure that contains two immiscible fluids together with electrodes such that the fluid can be rearranged with the cell.